Comments

This patch allows the run-time to be compiled with normalize scalars.
More specifically, it fixes a warning about initialiation overlays
when Ada.Strings.Unbounded.Aux is compiled with this pragma. Note
that the previous fix to pragma Suppress_Initialization is required.
The following test should compile without generating warnings:
1. pragma Warnings (Off);
2. with Ada.Strings.Unbounded.Aux;
3. pragma Warnings (On);
4. package RunTimeNS is
5. end;
when compiled in the presence of a gnat.adc file containing
pragma Normalize_Scalars
with the command
gnatmake -q runtimens -a -f
Tested on x86_64-pc-linux-gnu, committed on trunk
2011-08-02 Robert Dewar <dewar@adacore.com>
* a-stunau.ads: Add pragma Suppress_Initialization for Big_String
* freeze.adb (Warn_Overlay): Don't warn if initialization suppressed
* s-stalib.ads: Add pragma Suppress_Initialization for Big_String

Patch

Index: freeze.adb
===================================================================
--- freeze.adb (revision 177161)+++ freeze.adb (working copy)@@ -5874,15 +5874,16 @@
-- tested for because predefined String types are initialized by inline
-- code rather than by an init_proc). Note that we do not give the
-- warning for Initialize_Scalars, since we suppressed initialization
- -- in this case.+ -- in this case. Also, do not warn if Suppress_Initialization is set.
if Present (Expr)
and then not Is_Imported (Ent)
+ and then not Initialization_Suppressed (Typ)
and then (Has_Non_Null_Base_Init_Proc (Typ)
- or else Is_Access_Type (Typ)- or else (Normalize_Scalars- and then (Is_Scalar_Type (Typ)- or else Is_String_Type (Typ))))+ or else Is_Access_Type (Typ)+ or else (Normalize_Scalars+ and then (Is_Scalar_Type (Typ)+ or else Is_String_Type (Typ))))
then
if Nkind (Expr) = N_Attribute_Reference
and then Is_Entity_Name (Prefix (Expr))
Index: a-stunau.ads
===================================================================
--- a-stunau.ads (revision 176998)+++ a-stunau.ads (working copy)@@ -6,7 +6,7 @@
-- --
-- S p e c --
-- --
--- Copyright (C) 1992-2009, Free Software Foundation, Inc. --+-- Copyright (C) 1992-2010, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
@@ -38,7 +38,18 @@
pragma Preelaborate;
subtype Big_String is String (1 .. Positive'Last);
+ pragma Suppress_Initialization (Big_String);+ -- Type used to obtain string access to given address. Initialization is+ -- suppressed, since we never want to have variables of this type, and+ -- we never want to attempt initialiazation of virtual variables of this+ -- type (e.g. when pragma Normalize_Scalars is used).+
type Big_String_Access is access all Big_String;
+ for Big_String_Access'Storage_Size use 0;+ -- We use this access type to pass a pointer to an area of storage to be+ -- accessed as a string. Of course when this pointer is used, it is the+ -- responsibility of the accessor to ensure proper bounds. The storage+ -- size clause ensures we do not allocate variables of this type.
procedure Get_String
(U : Unbounded_String;
Index: s-stalib.ads
===================================================================
--- s-stalib.ads (revision 176998)+++ s-stalib.ads (working copy)@@ -57,9 +57,19 @@
pragma Preelaborate_05;
pragma Warnings (On);
- type Big_String_Ptr is access all String (Positive);+ subtype Big_String is String (1 .. Positive'Last);+ pragma Suppress_Initialization (Big_String);+ -- Type used to obtain string access to given address. Initialization is+ -- suppressed, since we never want to have variables of this type, and+ -- we never want to attempt initialiazation of virtual variables of this+ -- type (e.g. when pragma Normalize_Scalars is used).++ type Big_String_Ptr is access all Big_String;
for Big_String_Ptr'Storage_Size use 0;
- -- A non-fat pointer type for null terminated strings+ -- We use this access type to pass a pointer to an area of storage to be+ -- accessed as a string. Of course when this pointer is used, it is the+ -- responsibility of the accessor to ensure proper bounds. The storage+ -- size clause ensures we do not allocate variables of this type.
function To_Ptr is
new Ada.Unchecked_Conversion (System.Address, Big_String_Ptr);